Is it normal for a hyrdo tranny to whine?
 

I got my Paquette's 127 running real smooth after some carb work and a rewiring. I have never owned a cub cadet before and was somewhat surprised by the whining the tranny makes when in gear. Kind of annoying since the engine sounds so good. I would say it louder at slow speeds, but it might just be the noise of going faster that covers it up.

Is this whining normal? I wouldn't describe it as incredibly loud, but the pitch and volume does make me want to grab headphones when riding it. Hydro fluid is topped off.

Some whining is normal. If it is considered excessive, it could be cold temp related, or poor quality fluid, and a clogged filter. I would ensure that the fluid and filter is fresh and full.

I recommend Case IH Hytran and an OEM filter.

It is a 10 year old OEM filter on it with I'm assuming almost no hours. Fluid is about half 10 year old hy-tran, half brand new generic for IH from Rural King. There was a leak from a lose fitting I fixed and then topped it off.

It is NOT uncommon, for off brand hydraulic fluids to make the Sundstrand Hydro whine a bit, especially during colder weather. The whining fades away when the temp of the oil becomes warmer.

Are you running your engine at full rpm's ?
The hydro seems to whine more if you are not running your engine at full rpm's.